Acrobat Reader mobile apps (for iOS, Android, Windows Phone) are free PDF viewers. They do not support OCR (Optical Character Recognition).
However, you can purchase the online subscription service called Adobe Export PDF and use in Acrobat Reader mobile apps to convert PDF documents to other formats (e.g. Microsoft Word, Excel, PowerPoint).
Have you already purchased the Adobe Export PDF online subscription service? Would you make sure that you are signed in with your Adobe ID to use the service?